I figured I would post in here since the engine I have is a b18c. I have a racing radiator and the coolant in the reservoir keeps disappearing; I will fill it up and like a week later there is maybe half an inch of coolant left. I don't get it. I got told by someone who installs aftermarket parts that racing radiators don't need resevoirs and that I shouldn't worry about where mine is at, but that sounds really weird to me. I am by no means an expert in this area so I figured I'd ask. Every time I check it it's empty, BUT the car runs perfectly fine - plenty of power, vtec works, no smoke, no check engine light, and the temp gauge never even makes it to halfway, also I have no fluid puddles. Also, this has been going on for a long time now, like a year. Which made me start to wonder, was the guy I talked to right or should I keep filling it up?

 

Could be:

A) A coolant system leak. Check your hoses and your radiator.
B) A Head gasket leak, do a leak down test if you don't find anything visible when inspecting the hoses and radiator.

The guy you talked to was a moron. A coolant system should be sealed and have NO air in it. Definitely keep adding coolant until you find the issue. Are you sure it's not just air in the system working its way out?

 

Explain to me what a "racing radiator" is?

 

LOL you know damn well he means an aluminum dual or triple core.... probably off brand ebay.. probably the source of the leak.

 

You have a small leak most likely on the radiator somewhere, I had this issue till I pulled out the radiator and pulled away the fans and found a leak, this was on a cheap aluminum radiator from ebay, it was a temp radiator but lasted 2 years so I replaced it with a mishimoto unit.

 

Do you do your own oil change? If so, does the oil look milky? How about open the oil cap right after a run and look into the the hole with a flash light to see if the oil is milky or clean. Of course, you know milky oil means the coolant has found it's way into the oil passage and mix with the oil.

 

@burnoutboy - I didn't see any leaks when I checked the other day, I'll have to do a leak down test. Thanks for reassuring me. I thought what that guy said sounded off, coolant has been topped off.

@#itr1334 by racing radiator I meant a C&R Visteon Aluminum Racing Radiator, my bad, should have been more specific. No crappy ebay one.

@cw-itr - I do change my own oil and it looks fine, thank goodness. I haven't checked the oil cap after a run, but I'll do that soon.

Thanks for the advice everyone.

 

If you're constantly filling it up and it keeps disappearing, then it's most likely going to the head somewhere if there's no leaks.
Constantly check the oil to see if it's leaking there because it happened to my daily B20 Integra before.
but the fluid in the resovoir will fluctuate back and forth depending on the heat on a normal basis.

 

has it overheated before? It happened to my old 250k to 300k mile LS when I used the AC, but also had a history of overheating before. If I didnt use the AC, it just didnt the coolant as much.

Do you still have to top of the regular radiator cap also? Im inclined to think it is leaking somewhere in the head and evaporating if there is no smoke at the exhaust tip.

 

When I put my mishimoto in my 98 R, it took almost almost 1 week of driving ~72 miles, 5x/week to work before the coolant in my reservoir held its level. There were no leaks I guess it was slowly purging itself of air.

 

I had the exact same issue...turned out to be a head gasket!